2. Найдите значение выражения: 1) 0,3√900-1/4√64; 2) √0,64.49; 3) √3⁴.2⁶; 4) √40.√10- √20/√5.

1) $$0.3 \sqrt{900} - \frac{1}{4} \sqrt{64} = 0.3 \cdot 30 - \frac{1}{4} \cdot 8 = 9 - 2 = 7$$

2) $$\sqrt{0.64 \cdot 49} = \sqrt{0.64} \cdot \sqrt{49} = 0.8 \cdot 7 = 5.6$$

3) $$\sqrt{3^4 \cdot 2^6} = \sqrt{3^4} \cdot \sqrt{2^6} = 3^2 \cdot 2^3 = 9 \cdot 8 = 72$$

4) $$\sqrt{40} \cdot \sqrt{10} - \frac{\sqrt{20}}{\sqrt{5}} = \sqrt{40 \cdot 10} - \sqrt{\frac{20}{5}} = \sqrt{400} - \sqrt{4} = 20 - 2 = 18$$

Ответ: 1) 7; 2) 5.6; 3) 72; 4) 18